CVE-2026-5426

Published Apr 16, 2026

Last updated 12 days ago

CVSS critical 9.1
lms

Overview

Description
Hard-coded ASP.NET/IIS machineKey value in Digital Knowledge KnowledgeDeliver deployments prior to February 24, 2026 allows adversaries to circumvent ViewState validation mechanisms and achieve remote code execution via malicious ViewState deserialization attacks
Source
mandiant-cve@google.com
NVD status
Awaiting Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
9.1
Impact score
5.2
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity
CRITICAL

Weaknesses

mandiant-cve@google.com
CWE-321

Social media

Hype score
Not currently trending

  1. KnowledgeDeliver の脆弱性 CVE-2026-5426：実環境での悪用を Mandiant が警告 https://t.co/jOywxW67Dk KnowledgeDeliver の脆弱性 CVE-2026-5426 の原因は、システムの設定ファイルで管理される暗号鍵 (machineKey) が、複数の環境で共有さ

    @iototsecnews

    1 Jun 2026

    83 Impressions

    0 Retweets

    0 Likes

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    0 Replies

    0 Quotes

  2. CVE-2026-5426 zero-day in KnowledgeDeliver LMS exploited via hardcoded https://t.co/jaGYvH4XOK machine keys for ViewState deserialization attacks. Mandiant confirms Godzilla web shell deployment and Cobalt Strike beacons. #DFIR_Radar https://t.co/Cmy6PCIkKa

    @DFIR_Radar

    28 May 2026

    67 Impressions

    0 Retweets

    0 Likes

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    1 Reply

    0 Quotes

  3. KnowledgeDeliverにゼロデイ攻撃　認証なしで悪用可能なCVE-2026-5426　Godzilla web shell設置　全顧客環境で共有されたhttps://t.co/uRKtvxGxAV machine keyが原因　Mandiantが2025年末の攻撃対応で確認 #サイバーセキュリティ #ゼロ

    @WatcherN12588

    27 May 2026

    5 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    1 Reply

    0 Quotes

  4. Top 5 Trending CVEs: 1 - CVE-2026-45659 2 - CVE-2026-5426 3 - CVE-2026-48172 4 - CVE-2024-12802 5 - CVE-2026-8945 #cve #cvetrends #cveshield #cybersecurity https://t.co/4Fua3CAN6W

    @CVEShield

    27 May 2026

    99 Impressions

    0 Retweets

    2 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  5. 🩹マイクロソフト、SharePointの深刻なRCE脆弱性にパッチ（CVE-2026-45659） ⚠️ハッカーがKnowledgeDeliverのゼロデイを悪用し、Webシェルとバックドアを展開（CVE-2026-5426） 〜サイバーアラート5月27日〜 https://t.co/X6yz

    @MachinaRecord

    27 May 2026

    167 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  6. Hackers exploited a critical zero-day in KnowledgeDeliver to deploy the Godzilla web shell. The unauthenticated flaw (CVE-2026-5426) stems from a shared hardcoded machine key. https://t.co/0zB3krJwI3 #0day #KnowledgeDeliver #Godzilla #CVE #CybersecurityNews #ThreatResQ

    @ThreatResq

    27 May 2026

    84 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  7. Top 5 Trending CVEs: 1 - CVE-2026-5426 2 - CVE-2023-29218 3 - CVE-2026-2031 4 - CVE-2026-41096 5 - CVE-2024-53141 #cve #cvetrends #cveshield #cybersecurity https://t.co/4Fua3CAN6W

    @CVEShield

    26 May 2026

    145 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

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References

Sources include official advisories and independent security research.